The present invention relates to, for example, an encoding apparatus and an encoding method, a decoding apparatus and a decoding method, a recording medium, and a program suitable for encoding image signals with a higher
compression ratio for transmission or accumulation. In an
arithmetic coding section (58), from among the
syntax elements of input
image compression information, the frame / field flag is first encoded by a frame / field flag
context model (91). When the
macroblock to be processed is subjected to frame-based encoding, a frame-based
context model (92), specified in the current H.26L standard, is applied. On the other hand, when the
macroblock to be processed is subjected to field-based encoding, a field-based
context model (94) is applied for the
syntax elements described below. The present invention is applied to an
encoder for encoding image information and a decoder for decoding image information.